b'Climate Durability tal number of fluctuations for hot andlong-termperformanceofshingles cold weather shocks is maintained. for various Canadian climate zones. ThetestingprotocolfortheseA protocol combining the measured conditionsisdetailedinTable1.properties of the shingle with the cli-For example, in Zone 6, the weathermate severity may provide a single at-shock protocol spans 21 days. Fig- tribute as an indicator of the shingles ure 4 depicts a typical daily profilelong-term performance. 10To address for Zone 6, featuring four hot shocksthis, a framework for the development and four cold shocks per day. The tar- of a climate-dependent durability in-get temperature for a hot shock cycle,dex (CDDI) is presented. The CDDI representing the asphalt shingle sur- encompasses all measured properties face temperature, is twice the maxi- that are evaluated, and it also includes mum air temperature. Specifically indeterioration due to weather shocks. Zone 6, with an air temperature ofEach of the properties can contrib-102F(39C),thesurfacetempera- ute to shingle durability and be as-tureofdark-colouredasphaltshin- signedanimportancefactor.The gles can reach 172F (78C). importance factor can be assigned in Rainfalleventsaresimulatedinrelation to the corresponding impact betweenhotcycles.Afive-minuteeach property has on shingle fragility. rain event at a flow rate of 4.0 to 5.3Investigations of field failure modes gal./min (15 to 20 L/min) is incor- after major weather events can also porated into the protocol during theprovide a professional indication of hot shock cycle. This procedure is re- whichpropertycanminimizethe peated for two hot shocks per day, ex- weakest links in the resistance chain. cept in Zone 8, where the rain eventIn general terms:occurs only once a day. Considerashinglefroma source(S1)anditsmeasured Development of a Climate- properties as manufactured are Dependent Durability IndexP 1 , P 2 , P 3 , and P n .Figure 2: Weather shock framework summary. Note: GW = global warming. F = (1.8C) + 32. (CDDI) An importance factor (IF) is as-signed for each property as IF 1 , Incorporation of WeatherFor example, in the case of the ZoneApplication of WeatherBuildingenclosurecomponentIF 2 , IF 3 , and IF n .propertiesarequantifiedbasedonAssume S1 will be installed in Shocks into Experimental6,thereare66occurrencesofhotShock Parameters standardtestmethods.Forasphaltaparticularclimatezoneand Methodology cycles with a maximum temperatureAweathershockprotocolisshingles, the most common residen- exposed to weather shocks.of 102F (39C) for a design returndemonstratedbytakingadark- tial roof covering, CSA A123.5 8orThepropertiesofadurable Thesummaryoftheweatherperiod of 50 years. Additional dis- coloured asphalt roofing shingle asASTMD3462 9 providesspecifica- shingleshouldnotbesignificantly shock results for all the climate zonescussiononthedevelopmentofan example. For the dark-colouredtionsfortherequirementsofthereducedduetoweathershockex-of Canada is shown in Figure 3. Forweathershockparameterscanbeasphaltshingle,thecomponentstandard properties (tear, tensile andposure. Thus, the durability factor theframework,theconcentrationfound elsewhere. 5 surfacetemperaturewasdeter- fastener pull-through [FP]). They aredependsonthereductioninthe was on the maximum temperatureAlternatively, the weather shockmined to be twice that of the airnot test methods; rather, they refer- propertyofstrength.Iftheprop-for the hot weather shock to estab- data can also be visualized using thetemperature. 1,2,6,7Notethatdark- ence various test methods dependingertyreducesbeyondacertainper-lishtheworst-casescenario.Simi- existing climate zone map of Cana- coloured materials generally absorbon the property determination. Thecentage compared to its as-received larly, for the cold weather shock, theda, as shown in Figure 3. Zones 7Amore heat than light-coloured ma- referencedtestmethodsfailtoad- conditionafterweathershocks, minimum temperature was consid- and7Barecombinedforsimplic- terials. Using this information anddressthechangesinthepropertiesthat indicates that the durability of ered.Fora50-yearreturnperiod,ity and have the highest number offollowing the framework, in Figureduetoweathershocks.Thesetestthe shingle is low, while if the prop-the number of events is determinedweather shock occurrences for both2, the cold and hot weather shockmethods can be used before and af- erty reduction is low, that indicates for the hot and cold weather shocks.the hot and cold weather shocks. componentsurfacetemperaturester a shingle has been subjected to athat the durability of the shingle is and their respective number of oc- weather shock. Also, these test meth- higher. This article defines the dura-currences are determined. Since theods are designed for the evaluation ofbility factor (DF) depending on the materialsarecurrentlyevaluatedproductsasmanufactured.ASTMcorresponding per-cent reduction in atlabtemperature,thattempera- D3462specifiesthatphysicalandproperty strength as follows:turewasmaintainedasthebase- performance requirements after ap- DF = 0 when the reduction is line. Also, to replicate the cyclingplication and during in-service use ofgreater than or equal to 50 per that already naturally occurs withthe products are beyond the scope ofcent (reduction50 per cent)Think Safe, the change in seasons, the hot andthis material specification. In addi- DF = 1 when the reduction is Work Safe, cold weather shocks were alternat- tion, the measured properties (tear,greater than or equal to 30 per since 1988 ed. Table 1 summarizes a weathertensileandFP)arecriticalforthecent and less than 50 per cent shockprotocolfordark-colouredquality control determination in the(30 per centreduction 50 asphaltshingles. manufacturing process and standardper cent)Top-Line Roofing & Sheet-Metal Inc. specializes in the installation, repair, and maintenance ofAn important step for incorpo- designationsontheproductlabel- DF = 2 when the reduction is industrial roofs throughout Southern Ontario.rating the weather shock frameworkling.Ontheirown,noneofthesegreaterthan10percentbut OUR SERVICES: into routine lab testing is the deter- properties can provide an indicationless than 30 per cent (10 per Commercial roofing Re-roofing mination of the hot and cold cyclesof the roof coverings life-cycle per- cent reduction 30 per cent)Roof maintenance Skylight installation duration.Duringthis,oneshouldformance nor how it relates to theDF = 3 when the reduction is Roof inspection,Sheet metal flashing, evaluation & report fabrication & installation also account for the working hoursendusers(homeowners)decisionless than or equal to 10 per cent Historical restoration Retro-fit curb installation to ensure the practicality of the ex- topurchaseaparticularproduct.(reduction10 per cent)Emergency roof repairs periments. One way to achieve thisFor example, the existing wind clas- Basedontheabovediscussion, is by setting a practical duration forsifications (Class A, B, C, D or F) ofthe CDDI for a shingle can be ex-(905) 602-0760 the entire weather shock cycle andshingles are based on the static windpressed by the following equation:1325 Fewster Dr adjusting the duration of each cyclevelocity test. CDDI = P i (IF i DF i )Mississauga, ONL4W 1A2toplineroofing.ca accordingly. This approach must beThis creates a need for a science- where i = one of the various prop-achieved while ensuring that the to- basedindicatortodeterminetheerties that contribute to the CDDI.12ONTARIO ROOFING NEWSISSUE 4 2024/25 THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ORN'